Does aerobic exercise decrease brain activation?

In the present study, participants were randomly assigned to an exercise or a nonexercise group to measure brain activation (spontaneous EEG activity), affect, and cognitive functioning before and after a 15-min treatment period. Exercisers (a) sat quietly for 5 min, (b) exercised for 15 min, (c) recovered for 5 min, and (d) completed a 15-min vigilance task. Nonexercisers did not exercise. There was a significant (a) Condition x Band x Time interaction for EEG activity, (b) Condition x Time interaction for Activation-Deactivation Adjective Checklist (AD ACL) scores, and (c) Condition x Time interaction for reaction times (RTs). Post hoc tests showed (a) no significant group effects at the baseline and 15-min vigilance periods, and (b) significant group effects at the postexercise and 5-min vigilance periods. Exercisers had lower levels of brain activation (i.e., more theta and alpha activity and less beta activity), higher AD ACL scores, and slower RTs than nonexercisers during these periods.